Field of Disclosure
The disclosure generally relates to manipulability determinations for articulated models for use in vehicles for determining the usability of vehicle occupant package designs.
Description of the Related Art
Vehicle occupant packaging refers to the portions of the interior space of the vehicle that are occupied by the driver and passengers of the vehicle. Vehicle occupant packaging can include a number of different features including, for example, seat design, handbrake positioning and operation, steering wheel positioning and orientation, center console design, and door handle design and operation. Vehicle occupant packaging design refers to the general field that is concerned with designing vehicle occupant packaging so that a given vehicle's interior is both functional as well as comfortable. As vehicle designs vary widely and are iteratively improved with each new generation of vehicles, vehicle occupant packaging also needs to be redesigned and improved on a continual basis.
Typically, a new vehicle occupant packaging is tested by producing a full scale model of a given design, and then testing that design with a number of different human subjects. The human subjects used in the test will ideally be spread out across a wide range of physical characteristics including, for example, height, weight, gender, limb length (e.g., leg and arm length), strength, and joint range of motion. This helps ensure that a tested and approved vehicle occupant packaging will be operable by a significant majority of the human population.
Several different software simulation packages are available that allow for simulation of a vehicle occupant packaging design, as well as allow for simulation of testing of virtual subjects. These virtual subjects are computer models of human subjects, where the virtual subjects have the same variation of physical characteristics (e.g., height, weight, limb length) that are used in real life vehicle packaging design testing. Examples of these software packages include, for example, JACK offered by SIEMENS, and DELMIA offered by DASSAULT SYSTEMES.
These software packages improve the vehicle occupant packaging design process by allowing for design iteration without the need for a physical prototype for each design iteration. For example, software design packages allow a designer to test whether a human subject will fit in the given design (e.g., whether they will physically be able to reach the hand brake throughout its full range of motion). Further, these software packages allow calculation of a single static human posture when operating some aspect of the vehicle (e.g., the posture, fixed in time, when grasping the handbrake). Generally, these software packages calculate the single static posture using statistical regressions. However, these statistical regressions rely on a large amount of relevant experimental data in order to make posture predictions. As a result, relevant experimental data is not always available for the situation under consideration. For example, if you only have motion capture data of a hand-brake pull with no load, then posture cannot be determined when the load on the hand is 20 kilograms.
A drawback of existing design software packages is that they currently cannot provide the full range of information that is collected when conducting a live human subject test with a full scale test model. Consequently, it is still common practice to conduct a live test on a finalized (or semi-finalized) design, in order to make up for the deficiencies of existing software design packages.